Beautiful photo. It is hard making a shot like this work when you are limited on where to shoot from. You dont see to many downward angle waterfall shots with landscape so that is kind of the first thing that hit me as a little akward but I can still see it as being an interesting element in the shot.
Personally the only thing I can think of, just from viewing what options I would have had in the photo, is using an extremem wide angle and if I had too, to make the shot work, I personally would have made my way of that tree to get more distance from the falls and allow for more of them to be in the pic with the horizon. Of course I am talking like fish eye lens material here. Like I said, your a bit limited depending on what you have to work with when it comes to gear options and accessable areas to take the photo.
On the post processing techniques to work with what you have, I would recommend maybe a blue gradient filter in PS that would had some more deep blue to the sky and maybe mess with the toanl contrast in the pine trees to make them pop a bit more. But awesome shot, Tahoe is on my list of places to see, I hope to make it someday. Take care, Scott